SCFCdc4二元体的表面定向适应了基板无处不在的多重几何形状
Xiaojing Tang1, Stephen Orlicky, Zhenyuan Lin
1Centre for Systems Biology, Samuel Lunenfeld Research Institute, Toronto, Ontario, Canada M5G 1X5.
Cell
|June 19, 2007
概括
在SCF泛基因酶的D域形成二元体,增强基质泛基因化. 这种二元化优化了催化效率,通过在基板和无处不在链中适应不同的氨酸几何形状.
科学领域:
- * 分子和细胞生物学
- * 生物化学 * 生物化学
- * 结构生物学 * 结构生物学
背景情况:
- *SCF泛基因酶通过F盒蛋白适配器调解基质降解.
- * WD40重复F盒蛋白,如Cdc4和β-TrCP,具有对功能至关重要的D域.
- * 在SCF复合体中D域的二维结构和催化含义仍然不完全理解.
研究的目的:
- * 为了研究SCF泛素化酶复合体中D域介导的二分化过程的结构和功能后果.
- * 阐明SCF二分化在基质识别和乌比奎丁结合效率中的作用.
- * 模拟二维SCF复合体内的关键催化元件的空间布局.
主要方法:
- * 酵母Cdc4和人类β-TrCP的D域原体的结构分析.
- *生物化学试验评估D域中断对SCF (Cdc4) 活动对Sic1的影响.
- *小角度X射线散射 (SAXS) 测量以建模全SCF (Cdc4) 复杂结构.
主要成果:
- *酵母Cdc4和人类β-TrCP D域形成超螺旋式同型二元体.
- * D 域的干扰会影响SCF ((Cdc4) 对Sic1.1.等基质的活性.
- *SCF(Cdc4) 分解增强了无素的结合,而不会显著改变基质亲和力.
- *SAXS建模揭示了二维全SCF ((Cdc4) 复合体的表面配置.
结论:
- * D 域介导的二分化对于SCF 基因酶的催化效率至关重要.
- *二维结构定位基板和E2结合点,以适应不同的几何形状.
- *这种空间布局促进了高效的无处不在转移和基质降解.
相关概念视频
Protein Complexes with Interchangeable Parts
Groups of proteins may form a complex where each protein in this complex has a different role in the overall execution of the complex’s function. Often some of the proteins in the complex can be replaced by a closely related variant to give a complex that contains many of the same components yet is functionally distinct.
The SCF ubiquitin ligase is a protein complex of five individual proteins. This complex attaches ubiquitin to other target proteins to mark them for degradation. In order to...
The SCF ubiquitin ligase is a protein complex of five individual proteins. This complex attaches ubiquitin to other target proteins to mark them for degradation. In order to...
Prochirality
The concept of prochirality leads to the nomenclature of the individual faces of a molecule and plays a crucial role in the enantioselective reaction. It is a concept where two or more achiral molecules react to produce chiral products. A typical process is the reaction of an achiral ketone to generate a chiral alcohol. Here, the achiral reactant reacts with an achiral reducing agent, sodium borohydride, to generate an equimolar mixture of the chiral enantiomers of the product. For example, an...
Radicals: Electronic Structure and Geometry
This lesson delves into the geometry of a radical, which is influenced by the electronic structure of the molecule. The principle is similar to that of a lone pair, where the unpaired electron influences the geometry at the radical center.
Accordingly, the structure of a trivalent radical lies between the geometries of carbocations and carbanions. An sp2-hybridized carbocation is trigonal planar, while an sp3-hybridized carbanion is trigonal pyramidal. Here, the difference in geometry is...
Accordingly, the structure of a trivalent radical lies between the geometries of carbocations and carbanions. An sp2-hybridized carbocation is trigonal planar, while an sp3-hybridized carbanion is trigonal pyramidal. Here, the difference in geometry is...
Assembly of Signaling Complexes
Multiprotein signaling complexes are formed in a dynamic process involving protein-protein interactions at the cytoplasmic domain of transmembrane receptors or enzymatic and non-enzymatic proteins associated with the receptor. These complexes ensure the activation and propagation of intracellular signals that regulate cell functions.
Interaction domains in cell signaling
Interaction domains recognize exposed features of their binding partners containing post-translationally modified sequences,...
Interaction domains in cell signaling
Interaction domains recognize exposed features of their binding partners containing post-translationally modified sequences,...
Ligand Binding and Linkage
Allosteric proteins have more than one ligand binding site; the binding of a ligand to any of these sites influences the binding of ligands to the other sites. When a protein is allosteric, its binding sites are called coupled or linked. In the case of enzymes, the site that binds to the substrate is known as the active site and the other site is known as the regulatory site. When a ligand binds to the regulatory site, this leads to conformational changes in the protein that can influence the...
SN2 Reaction: Stereochemistry
In an SN2 reaction, the nucleophilic attack on the substrate and departure of the leaving group occurs simultaneously through a transition state. As the nucleophile approaches the substrate from the back-side, the configuration of the substrate carbon changes from tetrahedral to trigonal bipyramidal and then back to tetrahedral, leading to an inversion in the configuration of the product.
If the substrate is an achiral molecule at the α-carbon, the inversion of configuration is not observed.
If the substrate is an achiral molecule at the α-carbon, the inversion of configuration is not observed.


